WebSocket应用

前端：

export default{
    websoket: null,
    init:function(url){
        let _this = this;
        this.websoket = new WebSocket(url);
        this.websoket.onopen = function(event){//成功创建连接
            _this.onOpen(event);
        };
        this.websoket.onerror = function(event){//连接出现错误
            _this.onError(event);
        };
        this.websoket.onmessage = function(event){//收到服务器发送的信息
            _this.onMessage(event);
        };
        this.websoket.onclose = function(event){//关闭websocket
            _this.onClose(event);
        };
    },
    onOpen:function(event){
        console.log("建立连接");
        this.websoket.send("前端发送信息到后端");
    },
    onError:function(event){
        console.log("发生错误");
    },
    onMessage:function(event){
        console.log("服务器端发送信息至前端");
    },
    onClose:function(event){
        console.log("服务器端要求关闭websoket");
    }
}

服务器配置：有2种配置方式：注解模式（推荐方式）、XML配置
注解模式：
WebSocketConfig：配置类
package sino.com.websoket;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;

/**
  注：该类需要放在SpringMVC扫描路径下
  @Configuration//指明该类为Spring配置类
  @EnableWebSocket//声明该类支持websocket
 */
@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer{、
    @Resource TopoTreeHandler topoTreeHandler;
    @Resource TopoTreeInterceptor topoTreeInterceptor;
    /**
         支持websocket 的访问链接
        setAllowedOrigins:允许跨域
    */
    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry.addHandler(topoTreeHandler, "/testWebSoket.ws").addInterceptors(topoTreeInterceptor).setAllowedOrigins("*");
    }
}

XML配置模式：spring.xml配置文件中

<websocket:handlers allowed-origins="*">
     <websocket:mapping path="/testWebSoket.ws" handler="topoTreeHandler"/>
     <websocket:handshake-interceptors>
         <bean class="sino.com.websoket.TopoTreeInterceptor"/>
     </websocket:handshake-interceptors>
 </websocket:handlers>

TopoTreeInterceptor：拦截器
package sino.com.websoket;

import java.util.Date;
import java.util.Map;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.HandshakeInterceptor;

/**
 * Socket建立连接（握手）和断开
 * @author ZDB
 *
 */
@Component
public class TopoTreeInterceptor implements HandshakeInterceptor{
    @Override
    public boolean beforeHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse, WebSocketHandler esHandler,
            Map<String, Object> map) throws Exception {
        return true;
    }
    @Override
    public void afterHandshake(ServerHttpRequest arg0, ServerHttpResponse arg1, WebSocketHandler arg2, Exception arg3) {
        // TODO Auto-generated method stub
        
    }
    
}

TopoTreeHandler:
package sino.com.websoket;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;

@Component
@RequestMapping("/testWebSoket.ws")
public class TopoTreeHandler implements WebSocketHandler {
    public TopoTreeHandler() {
        System.out.println("初始化TopoTreeHandler对象");
    }
    //存储当前所有的在线用户socket
    //目前以userId为key,所以一个用户打开多个socket页面时只会在最新的页面推送消息
    private static final List<WebSocketSession> sessionMap = new ArrayList<>();

    
    //socket 连接常见时该方法被调用
    @Override
    public void afterConnectionEstablished(WebSocketSession webSocketSession) throws Exception {
        //在socket Interceptor中设置的参数、
        System.out.println("完成创建链接");
        sessionMap.add(webSocketSession);
        TopoTreeHandler.sendMessage(new TextMessage(new Date() + ""));
    }

    @Override
    public void handleMessage(WebSocketSession webSocketSession, WebSocketMessage<?> message) throws Exception {    
        System.out.println("前端发送的消息="+message.toString());
    }
    
    //连接出错时
    @Override
    public void handleTransportError(WebSocketSession webSocketSession, Throwable e) throws Exception {
        System.out.println("创建链接出错");
        if (webSocketSession.isOpen()) {
            webSocketSession.close();
        }
        sessionMap.remove(webSocketSession);
    }
    
    //连接关闭时
    @Override
    public void afterConnectionClosed(WebSocketSession webSocketSession, CloseStatus closeStatus) throws Exception {
        System.out.println("关闭链接");
    }

    @Override
    public boolean supportsPartialMessages() {
        // TODO Auto-generated method stub
        return false;
    }
    //向某个用户发送消息
    public void sendMessage(TextMessage message, String userId) {
//        WebSocketSession user = users.get(userId);
//        if (null != user && user.isOpen()) {
//            try {
//                user.sendMessage(message);
//            } catch (Exception e) {
//            }
//        }
    }
    
  //批量向所有用户发送消息
    public static void sendMessage(TextMessage message) {
        for (WebSocketSession session : sessionMap) {
            System.out.println("session="+session);
            if (session.isOpen()) {
                try {
                    session.sendMessage(message);
                } catch (Exception e) {
                }
            }
        }
    }
}